Document flattener



Dec 5, 1967 D. P. BUTTERBAUGH 3,355,829

DOCUMENT FLATTENER Filed Oct. '7, 1965 STACKER INVENTOR DENN|S P.BUTTERBAUGH @YM ATTORNEY United States Patent O 3,355,829 DOCUMENTFLATIENER Dennis P. Butterbaugh, Rochester, Minn., assignor tolluternational Business Machines Corporation, Armonk, N.Y., acorporation of New York Filed Oct. 7, 1965, Ser. No. 493,756 8 Claims.(Cl. itl- 156) ABSTRACT F THE DISCLOSURE The invention providesselectively operable pressure applying apparatus which operates with acaptured air supply. A flexible diaphragm is bonded or otherwise securedaround its perimeter to the edges of a flat rigid backplate preferablywith a slight tension preload. The rigid backplate is provided with oneor more holes which communicate with one or more flexible cups. Thellexible cups are provided with an edge which is lbonded to the-backplate about the hole. The bottom of each cup is attached to aspring biased armature of an electromagnet. Current through the magnetcoil holds the armature against an associated compression spring. Thiscauses the diaphragm t-o be flat against the rigid backplate and awayfrom `a surface plate. When the magnet is de-energized, the compressionspring forces the armature to collapse the associated flexible cup. Thedisplaced air in response to the cup being collapsed inflates thediaphragm which presses or iiattens an object such as a document againstthe surface plate. Atmospheric pressure aids the tension preload inreturning the diaphragm to a flat deated conditioniwhen the magnets areagain energized.

' This invention relates to selectively operable pressure applyingapparatus and more particularly to apparatus for flattening documentsagainst a viewing surface in a reading station during the readingperiod.

The invention finds particular utility in optical character readingmachines where the documents are read while stationary. In such machinesit is highly desirable to have all characters in the same plane forreading. However, these machines are required to process live documentswhich in many instances have been folded and otherwise have becomecrumpled from handling. Hence, it is necessary to flatten the documentsagainst a viewing surface during the reading operation wherebysubstantially all characters will be in the same plane. The documentsmust be flattened without smudging the print thereon and at high speedswith little noise. The document flattener also functions to seal off orprevent extraneous light from entering the reading area to interferewith the optical reading light collection system.

Heretofore, it has been the practice to inflate a diaphragm withexternal duid pressure to press the documents against the viewingsurface. In some instances, the documents have Ibeen sucked against theviewing surface by means of a vacuum, The use of external iluid pressureand vacuum sources generally require some exhaust system. Thisintroduces a time factor `which reduces the speed of operation. Thisinvention operates with a captured air supply. A flexible diaphragm isbonded or otherwise secured around its perimeter to the edges of a flatrigid back plate preferably with a slight tension preload. The rigidback plate is provided with one or more holes which communicate with oneor more flexible cups. The flexible cup or cups are provided with anedge which is bonded to the back plate about the hole. The bottom of thecup or cups is attached to a spring biased armature of an electromagnet.Current through the magnet coil holds the armature against theassociated compression spring. This 3,355,829 Patented Dec. 5, 1967 lCCcauses the diaphragm to be flat against the rigid back plate and thereis suicient clearance for the document to enter the reading stationbetween the diaphragm and the viewing surface plate. With the documentin place, the magnet is fle-energized. The compression spring forces thearmature to collapse the flexible cup. The displaced air in response tothe cup being collapsed inflates the diaphragm which presses or attensthe document against the viewing surface. Atmospheric pressure aids thetension preload in returning the diaphragm to a flat, deflatedcondition.

Accordingly, it is a principal object of the invention to provideimproved selectively operable pressure applying apparatus.

Another object of the invention is to provide selectively operablepressure applying apparatus which operates at relatively high speeds.

Still another object of the invention is to provide selectively operablepressure applying apparatus which is relatively quiet in operation.

A further object of the invention is to provide selectively operablepressure applying apparatus which operates with a captured air supply.

Yet another object of the invention is to provide selectively operablepressure applying apparatus which is relatively simple and inexpensive.

A more specific object of the invention is to provide selectivelyoperable pressure applying apparatus for iiattening documents against aviewing surface in a -reading] station in a character recognitionmachine.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of a preferred embodiment of the invention, as illustratedin the accompanying drawings.

In the drawings:

FIG. 1 is an exploded isometric view of apparatus embodying theinvention;

FIG. 2 is a fragmentary view partially in section with the electromagnetenergized and the diaphragm in its nondisplaced position;

FIG. 3 is a fragmentary view partially in section with the electromagnetde-energized and the diaphragm displaced; and,

FIG. 4 is a schematic view of a document reading machine incorporatingthe invention.

With reference to the drawings and particularly to FIG. l, the inventionis illustrated by way of example as including apparatus for atteningdocument 10 against viewing surface 11. Diaphragm 12, preferably made ofrubber, is `bonded or otherwise secured to the face of rigid plate 13about the perimeter thereof and preferably with a slight tensionpreload. Plate 13 is provided with one or more openings 14 which for thepurpose of providing a continuous level surface are provided with aconcentric recess 15 for receiving the annular lip 15 of flexible cup17. The lip 16 is bonded or otherwise suitably secured within the recess15. The exible cup l17 includes bellowslike or serrated sections 18 forpermitting expansion and contraction of the cup 17. The bottom 19 of cup17 is bonded or secured to a disc-like armature 20 of electromagnet 21.Electromagnet 21 includes a U-shaped yoke 22 formed from a plate 23 toflank the cylindrical electric coil 2.4 through which a core 25projects. Screw 27 threads into the core 25 to hold coil 24 in place.Compression spring 26 abuts plate 23 at one end and armature 20 at itsother end to bias armature 20 away from yoke 22 and core 25.

When coil 24 of electromagnet 21 is energized, armature 20 is attractedagainst yoke 22 and compresses spring 26 as seen in FIG. 2. The flexiblecup 17 under these conditions is expanded and the flexible diaphragm 12lies flat against the face of plate 13. This provides sucient clearancefor document to come between the flexible diaphragm 12 and the viewingplate 11. When it is desired to flatten document 10 against the viewingsurface of plate 11, electromagnet 21 is de-energized. Compressionspring 26 expands to move armature 20 away from yoke 22 and therebycollapse cup i7 as seen in FIG. 3. As cup 17 collapses, the air capturedtherewitnin is displaced and moves flexible diaphragm 12 toward plate 11to force or flatten the document 10 thereagainst. Coil 24 can benormally energized and upon stopping document 10 in the reading station,it can be de-energized. After the document is read, coil 24 is againenergized.

In FIG. 4, the invention is sho-wn as being incorporated into an opticalcharacter reading machine. Documents 10 are transported from hopper 30to reading station 40. The documents upon entering reading station 40are ilattened against viewing surface 11 as electromagnets Z1 arede-energized. In this particular instance, several electromagnets andassociated cups are used. The documents 10 are read in the stationary,attened condition. After a document has been read, the magnets 21 areenergized and the document is transported to one of two stackers 50.

From the foregoing it is seen that the invention provides selectivelyoperable pressure-applying apparatus. Further, it is seen that thisselectively operable pressure applying apparatus operates with acaptured air supply. This arrangement results in a selectively operablepressure applying apparatus which is capable of high speed operation andrelatively simple, inexpensive and quiet in operation.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

What is claimed is:

1. Selectively operable pressure applying apparatus comprising:

a rigid plate having at least one aperture therein;

a exible diaphragm secured to one side of said plate to cover saidaperture;

an expandable and collapsible cup closed at one end and secured at itsopen end to the other side of said plate about said aperture; and

means for selectively expanding and collapsing said cup whereby the airin said cup is displaced to move said diaphragm against and away fromsaid plate, respectively.

2. The pressu-re applying apparatus of claim 1 wherein said selectivelyoperable expanding and collapsing means comprises:

an armature attached to said cup;

a selectively operable electromagnet for attracting said armaturethereto upon being energized; and

means for biasing said armature away from said electromagnet.

3. The pressure applying apparatus of claim 1 where said diaphragm isattached to said plate with a tension preload.

4. The pressure applying apparatus of claim 1 where said cup is providedwith serrated walls to facilitate expanding and collapsing said cup.

5. A document tlattener comprising:

a fixed backing plate, a rigid plate spaced from said backing plate topermit a document to pass therebetween, said rigid plate having at leastone aperture therein;

a flexible diaphragm secured to said rigid plate to face sa'd backingplate and cover said aperture;

an expandable and collapsible cup closed at one end and secured at itsother end to said rigid plate about said aperture; and,

means for selectively expanding and collapsing said cup whereby uponexpanding said cup the air therein is displaced to move said diaphragmagainst said rigid plate and upon being collapsed, the air therein isdisplaced to move said diaphragm toward said backing plate to flattensaid document thereagainst.

6. The document flattener of claim 5 wherein said dia-v phragm issecured to said rigid plate with a tension preload.

7. The document flattener of claim 5 wherein said se* lectively operableexpanding and collapsing means comprises:

an armature attached to the closed end of said cup;

a selectively operable electromagnet for attracting said armaturethereto upon being energized to expand said cup; and,

means for biasing said armature away from said electromagnet wherebyupon said electromagnet being deenergized said cup is collapsed.

8. The document flattener of claim 5 wherein said cup is provided withserrated walls to facilitate expansion and collapsion of said cup.

References Cited UNITED STATES PATENTS 8/1901 Gerlach 95-76 X 5/1933Sherts 40-156 OTHER REFERENCES EUGENE R. CAPOZIO, Primary Examiner.

W. J. CONTRERAS, Assistant Examiner.

1. SELECTIVELY OPERABLE PRESSURE APPLYING APPARATUS COMPRISING: A RIGIDPLATE HAVING AT LEAST ONE APERTURE THEREIN; A FLEXIBLE DIAPHRAGM SECUREDTO ONE SIDE OF SAID PLATE TO COVER SAID APERTURE; AN EXPANDABLE ANDCOLLAPSIBLE CUP CLOSED AT ONE END AND SECURED AT ITS OPEN END TO THEOTHER SIDE OF SAID PLATE ABOUT SAID APERTURE; AND MEANS FOR SELECTIVELYEXPANDING AND COLLAPSING SAID